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United States Patent | 5,315,284 |
Bentley ,   et al. | May 24, 1994 |
A zero-crossing detector for asynchronous detection of threshold transitions in a digitally sampled signal waveform. The Asynchronous Digital Threshold Detector (ADTD) receives a digitized self-clocking data readback waveform and provides the relative location of a zero-crossing within the sample period where it occurs. The digital output, which is useful for recovering data and clock signals, is in a digital form that can be used directly by a certain class of asynchronous digital phase detector systems. The ADTD is entirely digital and can be embodied in a low power configuration using CMOS technology.
Inventors: | Bentley; Steven R. (Tucson, AZ); Hutchins; Robert A. (Tucson, AZ); Melas; Constantin M. (Los Gatos, CA); Sutardja; Pantas (San Jose, CA) |
Assignee: | International Business Machines Corporation (Armonk, NY) |
Appl. No.: | 073921 |
Filed: | June 7, 1993 |
Current U.S. Class: | 340/146.2; 327/78; 327/79; 360/51 |
Intern'l Class: | G05B 001/03; G06F 007/02; H03K 005/153 |
Field of Search: | 340/146.2 307/354,351 328/151 |
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